Image forming apparatus that controls way of discharging sheet bundles, control method for image forming apparatus, and storage medium

ABSTRACT

An image forming apparatus which is capable of preventing printed matter from being discharged in a way that is not intended by a user. A printer unit prints an image on a sheet. A sheet bundle including a sheet on which the image has been printed by the printer unit is conveyed and stacked on a discharging tray, which has a stopper that prevents the stacked sheet bundle from falling down to the floor. A state of the stopper is detected, and based on the detected state, notification is provided to the user.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image forming apparatus, a control method for the image forming apparatus, and a storage medium.

2. Description of the Related Art

Conventionally, image forming apparatuses are known which have a discharging tray onto which bundles of recording sheets that have been subjected to a saddle-stitching process are discharged (hereafter referred to as “sheet bundles”) (see, for example, Japanese Laid-Open Patent Publication (Kokai) No. 2010-168134). The discharging tray has a stopper, which holds sheet bundles discharged from an image forming apparatus on the discharging tray to prevent the sheet bundles from falling down to the floor.

In the case where the discharging tray is equipped with the stopper described above, the discharging tray becomes full and printing is suspended when printed matter more than a predetermined number of sheets (a predetermined number of bundles) is discharged. In this case, to resume printing, a user needs to remove the printed matter from the discharging tray.

On the other hand, it is also conceivable that the stopper for holding printed matter on the discharging tray is configured to be removable (openable). When the stopper is removed from the discharging tray, printed matter slips off the discharging tray, but if a collecting box is placed in advance below the discharging tray, the printed matter is put in the collecting box. Namely, if a collecting box in which a larger amount of printed matter than an amount allowed to be stacked on the discharging tray at a time is placed, the number of times printing is suspended decreases to reduce time and effort for a user.

However, there are cases where, for example, a certain user removes the stopper, places the collecting box under the discharging tray, and after printing is completed, carries the collecting box with the stopper removed and leaves the image forming apparatus. In this case, when another user who desires to hold sheet bundles on the discharging tray using the stopper starts printing without being aware that the stopper has been removed, the sheet bundles fall down to the floor, and dirt is adhered to the sheet bundles on the floor. This is contrary to the intention of the user who desired to hold the sheet bundle on the discharging tray using the stopper.

Also, when a user who desires to put printed matter in the collecting box without using the stopper starts printing without being aware that the stopper is attached to the discharging tray, printing is suspended earlier than expected by the user. This requires time and effort to remove printed matter from the discharging tray. Further, if a user temporarily stays away from the image forming apparatus after printing is started, printing cannot be resumed when printing is suspended, and the state of suspension continues until the user comes back, resulting in low productivity.

SUMMARY OF THE INVENTION

The present invention provides an image forming apparatus and a control method therefor, which are capable of preventing printed matter from being discharged in a way that is not intended by a user, as well as a storage medium.

Accordingly, the present invention provides an image forming apparatus comprising a printing unit configured to print an image on a sheet, a conveying unit configured to convey a sheet bundle including a sheet on which the image has been printed by the printing unit, a discharging tray configured to have the sheet bundle, which has been conveyed by the conveying unit, stacked thereon and have a stopper that prevents the stacked sheet bundle from falling onto a floor, a detection unit configured to detect a state of the stopper, and a notification unit configured to provide notification to a user based on a result of the detection by the detection unit.

According to the present invention, a state of the stopper provided in the discharging tray on which printed matter is stacked is detected, and based on the detected state, notification is provided to the user. This prevents printed matter from being discharged in a way that is not intended by the user.

Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram schematically showing an arrangement of an image forming system including an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram schematically showing an internal arrangement of the image forming apparatus in FIG. 1.

FIG. 3 is a diagram schematically showing an internal arrangement of a printer unit in FIG. 2.

FIG. 4 is a diagram schematically showing an internal arrangement of a finisher unit in FIG. 2.

FIGS. 5A and 5B are diagrams useful in explaining a sheet bundle stacking unit in FIG. 4.

FIG. 6 is a flowchart showing the procedure of a display process which is carried out by a CPU in FIG. 2.

FIGS. 7A and 7B are views useful in explaining confirmation display screens displayed in steps S606 and S606 in FIG. 6.

FIG. 8 is a flowchart showing a first variation of the procedure of the display process in FIG. 6.

FIG. 9A is a flowchart showing a second variation of the procedure of the display process in FIG. 6. FIG. 9B is a flowchart showing the procedure of a first print job which is executed in step S901 in FIG. 9A. FIG. 9C is a flowchart showing the procedure of a second print job which is executed in step S902 in FIG. 9A.

FIG. 10 is a flowchart showing a third variation of the procedure of the display process in FIG. 6.

DESCRIPTION OF THE EMBODIMENTS

The present invention will now be described in detail with reference to the drawings showing an embodiment thereof.

FIG. 1 is a block diagram schematically showing an arrangement of an image forming system 100 including an image forming apparatus 101 according to an embodiment of the present invention.

The image forming system 100 in FIG. 1 has the image forming apparatus 101 and a computer terminal 102, and the image forming apparatus 101 and the computer terminal 102 are connected together via a network 103. A user operates the computer terminal 102 to instruct the image forming apparatus 101 to, for example, execute print job.

FIG. 2 is a block diagram schematically showing an internal arrangement of the image forming apparatus 101 in FIG. 1.

The image forming apparatus 101 in FIG. 2 has a scanner unit 201, a printer unit 202, an operating unit 203, a controller 204, and a finisher unit 205, and the controller 204 has a CPU 206, a work memory 207, an image processing unit 208, an image memory 209, an HDD 210, and a network I/F 211.

The scanner unit 201, the printer unit 202, the work memory 207, the image processing unit 208, the HDD 210, and the network I/F 211 are connected to one another via the CPU 206. The image memory 209 is connected to the image processing unit 208 and the HDD 210, the network I/F 211 is connected to the network 103, and the finisher unit 205 is connected to the printer unit 202. The scanner unit 201 and the printer unit 202 are connected to the image processing unit 208 via image signal lines 212 and 213, respectively.

The scanner unit 201 reads an original and obtains image data corresponding to the original. The printer 202 prints, for example, image data, which is obtained by the scanner unit 201, on a recording sheet. The operating unit 203 has hardware keys, an operating panel, and so on, and a user inputs instructions to the image forming apparatus 101 through the hardware keys and the operating panel. It should be noted that the operating panel may have, for example, a liquid crystal monitor, and for example, information on the image forming apparatus 101 is displayed on the liquid crystal monitor. The finisher unit 205 carries out a finishing process such as a stapling process, or a saddle stitching process including two processes, i.e. a stapling process and a folding process.

The CPU 206 controls the component elements of the image forming apparatus 101 by executing programs stored in the HDD 210. The work memory 207 temporarily stores, for example, programs which are executed by the CPU 206 so as to control the component elements of the image forming apparatus 101. The image processing unit 208 subjects, for example, image data read by the scanner unit 201 to a shading process and various types of filtering processes. The image processing unit 208 also converts page description language data, which is obtained by way of the network I/F 211, into image data in a printable format. The image memory 209 temporarily stores, for example, image data read by the scanner unit 201. The HDD 210, which is a high-capacity storage device, stores image data and various programs.

FIG. 3 is a diagram schematically showing an internal arrangement of the printer unit 202 in FIG. 2.

The printer unit 202 in FIG. 3 has a polygon mirror 301, mirrors 302 to 313, photosensitive drums 314C, 314M, 314Y, and 314K, toner cartridges 315C, 315M, 315Y, and 315K, developing devices 316C, 316M, 316Y, and 316K, a transfer belt 318, a transfer roller 318, cassettes 319 and 320, a manual feed tray 321, a conveying belt 322, a fixing device 323, a flapper 324, and a path 325.

Image data which is printed on a recording sheet is comprised of four colors, i.e. cyan (C), magenta (M), yellow (Y), and black (K), and a semiconductor laser drive unit (not shown) irradiates the photosensitive drums 314C, 314M, 314Y, and 314K, which are electrically charged, with laser light corresponding to the respective colors by way of the polygon mirror 301 and the mirrors 302 to 313. As a result, electrostatic latent images are formed on the photosensitive drums 314C, 314M, 314Y, and 314K, and the electrostatic latent images are developed by tonner supplied from the toner cartridges 315C, 315M, 315Y, and 315K and the developing devices 316C, 316M, 316Y, and 316K, and this forms toner images on the photosensitive drums 314C, 314M, 314Y, and 314K.

The generated toner images are transferred onto the transfer belt 317, and at the transfer roller 318, the toner images transferred onto the transfer belt 317 are transferred onto a surface of a recording sheet conveyed from any one of the cassettes 319 and 320 and the manual feed tray 321. The recording sheet onto the surface of which the toner images have been transferred is conveyed to the fixing device 323 via the conveying belt 322, and the toner images are fixed onto the recording sheet by the fixing device 323. The recording sheet with the toner images fixed thereon is conveyed to the path 325 via the flapper 324, then changes the direction in which it is headed, and is discharged from the printer unit 202.

FIG. 4 is a diagram schematically showing an internal arrangement of the finisher unit 205 in FIG. 2.

The finisher unit 205 in FIG. 4 has a sheet bundle bringing-in unit 401, a Z-folding machine 402, a path 403, rollers 404, an escape tray 405, a puncher 406, a stapler 407, a stack tray 408, a saddle stitcher 409, discharging rollers 410 a and 410 b, and a sheet bundle stacking unit 411, and the sheet bundle stacking unit 411 has a saddle tray 412.

A sheet bundle Sb comprised of a plurality of recording sheets discharged from the printer unit 202 is brought into the finisher unit 205 from the sheet bundle bringing-in unit 401, and when the sheet bundle Sb is to be folded in a Z-form, the sheet bundle Sb is conveyed to the Z-folding machine 402 and folded in a Z-form. When the sheet bundle Sb is not to be folded in a Z-form, the sheet bundle Sb is conveyed to the rollers 404 via the path 403 without being conveyed to the Z-folding machine 402.

When no finishing process is to be carried out for the sheet bundle Sb brought into the finisher unit 205 from the sheet bundle bringing-in unit 401, the sheet bundle Sb is directly discharged onto the escape tray 405. When the puncher 406 is to carry out a punching process in which it punches the sheet bundle Sb and/or when the stapler 407 is to carry out a stapling process in which it staples the sheet bundle Sb, the sheet bundle Sb is discharged onto the stack tray 408. When the saddle stitcher 409 has carried out a stapling process for the sheet bundle Sb and also has carried out a saddle stitching process in which it folds the sheet bundle Sb in two, the sheet bundle Sb is discharged onto the saddle tray 412 via the discharging rollers 410 a and 410 b.

FIGS. 5A and 5B are diagrams useful in explaining the sheet bundle stacking unit 411 in FIG. 4.

The sheet bundle stacking unit 411 in FIGS. 5A and 5B has a stopper unit 501, a collecting box 502, a mode sensor 503, and a stacked-sheet presence-absence sensor 504 as well as the saddle tray 412 described above, and the stopper unit 501 is comprised of a stopper 501 a and a sheet bundle stacking surface 501 b. The stopper 501 a prevents the sheet bundles Sb stacked on the sheet bundle stacking surface 501 b from falling down to the floor.

One end of the sheet bundle stacking surface 501 b is fixed to the finisher unit 205, and the stopper unit 501 is fixed so as to pivotally rotate about the fixed end of the sheet bundle stacking surface 501 b. The stopper unit 501 rotates in, for example, a range indicated by an arrow d1 in the figure. One end of the saddle tray 412 is fixed to the finisher unit 205, and the fixed end of the saddle tray 412 is at a higher level than the other end of the saddle tray 412 with respect to a vertical direction. Thus, the sheet bundle Sb discharged onto the saddle tray 412 moves in a direction indicated by an arrow d2 in the figure.

By attaching the stopper unit 501 to the saddle tray 412 or removing the stopper unit 501 attached to the saddle tray 412 from the saddle tray 412, the user selects a desired way, for example, a normal mode or a through mode, to be described later, as a way of discharging the sheet bundle Sb onto the saddle tray 412 (hereafter referred to as “the stacking mode”).

Specifically, when the user desires to hold the sheet bundle Sb on the saddle tray 412 by restricting movement of the sheet bundle Sb in the direction indicated by the arrow d2 in the figure, he or she selects the normal mode in which the stopper unit 501 is attached to the saddle tray 412 as the stacking mode (see FIG. 5A). When the user desires to collect the sheet bundle Sb into the collecting box 502 placed in advance, he or she selects the through mode in which the stopper unit 501 is removed from the saddle tray 412 as the stacking mode (see FIG. 5B). It should be noted that when the user selects the normal mode as the stacking mode, the maximum number of sheet bundles Sb allowed to be held on the saddle tray 412 by the stopper 501 a (hereafter referred to as “the maximum number of sheet bundles”) is stored in advance in the HDD 210.

The mode sensor 503 detects whether or not the stopper unit 501 is attached to the saddle tray 412 and determines the stacking mode selected by the user. When the stopper unit 501 is attached to the saddle tray 412, the mode sensor 503 determines that the normal mode is selected as the stacking mode, and when the stopper unit 501 is removed from the saddle tray 412, the mode sensor 503 determines that the through mode is selected as the stacking mode.

Namely, whether the normal mode is set or the through mode is set is determined based on the position of the stopper 501 using the mode sensor 503, and hence the stacking mode is easily determined, which eliminates the need to have an additional device or the like for determination.

The stacked-sheet presence-absence sensor 504 is fixed to the sheet bundle stacking surface 501 b of the stopper unit 501, and when the normal mode is selected as the stacking mode, the stacked-sheet presence-absence sensor 504 projects out from the sheet bundle stacking surface 501 b to detect whether or not any sheet bundle Sb is stacked on the sheet bundle stacking surface 501 b. It should be noted that in place of the mode sensor 503, the stacked-sheet presence-absence sensor 504 may determine whether the normal mode or the through mode is selected as the stacking mode as will be described later with reference to FIG. 10.

A description will now be given of a display process which is a control method for the image forming apparatus according to the embodiment of the present invention.

FIG. 6 is a flowchart showing the procedure of the display process which is carried out by the CPU 206 in FIG. 2.

Referring to FIG. 6, first, the CPU 206 analyzes a print job of which execution has been ordered by the user and determines whether or not sheet bundles Sb corresponding to the print job are to be discharged onto the saddle tray 412 (step S601). As a result of the determination in the step S601, when the sheet bundles Sb are not to be discharged onto the saddle tray 412, the CPU 206 executes the print job and discharges the sheet bundles Sb onto a discharge tray other than the saddle tray 412, for example, the escape tray 405 or the stack tray 408 (step S602) and terminates the present process. As a result of the determination in the step S601, when the sheet bundles Sb are to be discharged onto the saddle tray 412, the CPU 206 determines whether or not the through mode is selected as the stacking mode (that is, whether or not the stopper unit 501 has been removed) (step S603).

As a result of the determination in the step S603, when the through mode is selected as the stacking mode, the CPU 206 displays a confirmation display screen 700 a (first message) in FIG. 7A, to be described later, on the operating unit 203 (provide notification to the user) (step S604). As a result of the determination in the step S603, when the through mode is not selected as the stacking mode, the CPU 206 determines whether or not the number of sheet bundles Sb to be discharged onto the saddle tray 412 is greater than the maximum number of sheet bundles (step S605).

As a result of the determination in the step S605, when the number of sheet bundles Sb to be discharged onto the saddle tray 412 is greater than the maximum number of sheet bundles (i.e. greater than a predetermined value), the CPU 206 displays a confirmation display screen 700 b (second message) in FIG. 7B, to be described later, on the operating unit 203 (provide notification to the user) (step S606). On the other hand, as a result of the determination in the step S605, when the number of sheet bundles Sb to be discharged onto the saddle tray 412 is equal to or smaller than the maximum number of sheet bundles, the CPU 206 skips the steps S606 and S607, executes the print job, discharges the sheet bundles Sb onto the saddle tray 412 (step S608), and terminates the present process. It should be noted that when it is determined in the step S603 that the through mode is not selected as the stacking mode, the process may directly proceed to the step S608 with the step S605 skipped.

Here, the confirmation display screen 700 a has a confirmation display section 701 a, an OK button 702 a, and a cancel button 703 a as shown in FIG. 7A, and the confirmation display screen 700 b has a confirmation display section 701 b, an OK button 702 b, and a cancel button 703 b as shown in FIG. 7B.

The confirmation display screen 700 a is displayed on the operating unit 203 when the through mode is selected as the stacking mode, and the confirmation display section 701 a informs the user that the through mode is selected as the stacking mode and indicates that it is necessary to check whether the collecting box 502 in which sheet bundles Sb are collected after printing is placed. Also, when the collecting box 502 is not placed, the confirmation display section 701 a indicates that it is necessary to change the stacking mode from the through mode to the normal mode. The OK button 702 a is depressed to execute a print job, and the cancel button 703 a is depressed to cancel execution of a print job.

The confirmation display screen 700 b is displayed on the operating unit 203 when the normal mode is selected as the stacking mode, and the confirmation display section 701 b informs the user that the normal mode is selected as the stacking mode. The confirmation display section 701 b also warns that printing will be suspended halfway because the number of sheet bundles Sb to be discharged onto the saddle tray 412 is greater than the maximum number of sheet bundles, and indicates that it is necessary to change the stacking mode from the through mode to the normal mode and place the collecting box 502 so as to prevent printing from being suspended. The OK button 702 b is depressed to execute a print job, and the cancel button 703 b is depressed to cancel execution of a print job.

Referring to FIG. 6 again, the CPU 206 determines whether or not the OK button 702 a, 702 b on the confirmation display screen 700 a, 700 b displayed in the step S604, S606 has been depressed (step S607). As a result of the determination in the step S607, when the OK button 702 a, 702 b has been depressed, the process proceeds to the step S608, in which the CPU 206 in turn executes the print job, discharges the sheet bundles Sb onto the saddle tray 412, and terminates the present process. On the other hand, when the cancel button 703 a, 703 b has been depressed, the CPU 206 cancels execution of the print job (step S609) and terminates the present process.

According to the process in FIG. 6, when it is determined that the normal mode in which the stopper mode 501 is used is selected as the stacking mode (NO in the step S603), and the number of sheet bundles Sb to be discharged onto the saddle tray 412 is greater than the maximum number of sheet bundles (YES in the step S605), the confirmation display screen 700 b is displayed to check whether or not to change the stacking mode from the normal mode to the through mode (step S606).

Since the confirmation display screen 700 b indicates that the number of sheet bundles Sb to be discharged onto the saddle tray 412 is greater than the maximum number of sheet bundles, and printing will be suspended, the user recognizes the need to change the stacking mode from the normal mode to the through mode. This circumvents a situation in which the user does not recognize that all sheet bundles Sb have not been discharged onto the saddle tray 412 until he or she collects the sheet bundles Sb.

Moreover, according to the process in FIG. 6, when it is determined that the through mode is selected as the stacking mode (YES in the step S603), the confirmation display screen 700 a is displayed (step S604). The confirmation display screen 700 a informs the user that the through mode is selected and also indicates that it is necessary to check whether or not the collecting box 502 in which the sheet bundles Sb are to be collected is placed.

As a result, the user who desires to perform printing in the normal mode recognizes that the through mode is set, and hence by changing the stacking mode to the normal mode, the user prevents the sheet bundles Sb from falling down to the floor and prevents dirt from being adhered to the sheet bundles Sb that have fallen down to the floor. Further, according to the process in FIG. 6, since the user recognizes the need to place the collecting box 502 in which the sheet bundles Sb are to be collected is placed, a situation in which printing is started without the collecting box 502 being placed by the user, the sheet bundles Sb fall down to the floor, and dirt is adhered to the sheet bundles Sb that have fallen down to the floor is avoided. Namely, printed matter is prevented from being discharged in a way that is not intended by the user.

A description will now be given of a display process which is a first variation of the control method for the image forming apparatus according to the embodiment of the present invention.

FIG. 8 is a flowchart showing a first variation of the procedure of the display process in FIG. 6.

The display process in FIG. 8 is carried out so as to have the user to see the confirmation display screen 700 a, 700 b displayed on the operating unit 203 of the image forming apparatus 101 when execution of a print job is ordered by the user through the computer terminal 102. Accordingly, the process in FIG. 8 is based on the assumption that the image forming apparatus 101 has an authentication function. It should be noted that processes in steps S601 to S609 in FIG. 8 are the same as those in the steps S601 to S609 in FIG. 6, and therefore, only features different from the processes in FIG. 6 will be described below.

Referring to FIG. 8, as a result of the determination in the step S603, when the through mode is selected as the stacking mode, the CPU 206 determines whether or not a user who sent a print job to the image forming apparatus 101 has directly input, for example, a user ID and a password to the operating unit 203, and authentication of the user has been performed (step S801). As a result of the determination in the step S801, when authentication of the user has not been performed, the process returns to the step S801, and when authentication of the user has been performed, the CPU 206 determines again whether or not the through mode is selected as the stacking mode (step S802). As a result of the determination in the step S802, when the through mode is selected as the stacking mode, the process proceeds to the step S604, and when the through mode is not selected, the process proceeds to the step S605.

On the other hand, as a result of the determination in the step S603, when the through mode is not selected as the stacking mode, the CPU 206 determines whether or not the number of sheet bundles Sb to be discharged onto the saddle tray 412 is greater than the maximum number of sheet bundles (step S803).

As a result of the determination in the step S803, when the number of sheet bundles Sb to be discharged onto the saddle tray 412 is greater than the maximum number of sheet bundles, the process proceeds to the step S801, and when the number of sheet bundles Sb to be discharged onto the saddle tray 412 is equal to or smaller than the maximum number of sheet bundles, the process proceeds to the step S608 with the steps S604 to S607 and the steps S801 and S802 skipped. It should be noted that when it is determined in the step S603 that the through mode is not selected as the stacking mode, the process can directly proceed to the step S608 with the step S803 skipped.

According to the process in FIG. 8, when authentication of the user has been performed (YES in the step S801), and the through mode is selected as the stacking mode (YES in the step S802), the confirmation display screen 700 a described above is displayed (step S604). When authentication of the user has been performed (YES in the step S801), the normal mode is selected as the stacking mode (NO in the step S802), and the number of sheet bundles Sb to be discharged onto the saddle tray 412 is greater than the maximum number of sheet bundles (YES in the step S605), the confirmation display screen 700 b described above is displayed (step S606).

It should be noted that when authentication of the user is to be performed in the step S801, the user is close to the image forming apparatus 101 so as to directly input, for example, a user ID and a password to the operating unit 203, the user realizably sees the confirmation display screen 700 a, 700 b displayed on the operating unit 203 in the step S604, S606 and reliably recognizes whether the through mode is set or the normal mode is set.

Moreover, according to the process in FIG. 8, whether or not the through mode is selected as the stacking mode is determined (step S603), authentication of the user is performed (step S801), and whether or not the through mode is selected as the stacking mode is determined again (step S802).

In the step S603, for example, there may be a case where before authentication of the user is performed after it is determined that the through mode is selected as the stacking mode, the stacking mode is changed from the through mode to the normal mode by another user. In this case, if the user who has not recognized that the stacking mode was changed uses the image forming apparatus 101, the image forming apparatus 101 discharges sheet bundles Sb onto the saddle tray 412 in the normal mode. In the normal mode, when the number of sheet bundles Sb to be discharged is greater than the maximum number of sheet bundles, the image forming apparatus 101 automatically suspends printing, and hence all the sheet bundles Sb are not discharged onto the saddle tray 412 against a user's will.

To cope with this, whether or not the through mode is selected is determined again in the step S802 to prevent the process from proceeding while the normal mode is still selected as the stacking mode against a user's will. After that, in the through mode selected as the stacking mode again, all the sheet bundles Sb are collected into the placed collecting box 502, and this prevents printed matter from being discharged in a way that is not intended by the user.

A description will now be given of a display process which is a second variation of the control method for the image forming apparatus according to the embodiment of the present invention.

FIG. 9A is a flowchart showing a second variation of the procedure of the display process in FIG. 6.

The process in FIG. 9A is carried out when sheet bundles Sb corresponding to at least two print jobs of which execution has been ordered by the same user are successively discharged onto the saddle tray 412 in the normal mode or the through mode. In the process in FIG. 9A, it is assumed, for example, that sheet bundles Sb1 and Sb2 corresponding to a first print job and a second print job, respectively, of which execution has been ordered by the same user are successively discharged onto the saddle tray 412 in the normal mode or the through mode.

According to this variation, the first print job in FIG. 9B (step S901), to be described later, and the second print job in FIG. 9C (step S902), to be described later, are successively executed.

FIG. 9B is a flowchart showing the procedure of the first print job which is executed in the step S901 in FIG. 9A. Processes in steps S601 to S609 in FIG. 9B are the same as those in the steps S601 to S609 in FIG. 6, and therefore, only features different from the processes in FIG. 6 will be described below.

Referring to FIG. 9B, as a result of the determination in the step S607, when the OK button 702 a, 702 b has been depressed, the CPU 206 stores, in the work memory 207, stacking mode information indicative of whether the stacking mode selected when the first print job is to be executed is the normal mode or the through mode and also stores, in the work memory 207, user information on a user who has ordered execution of the first print job, for example, a user name and a date and time at which execution of the first print job was ordered (step S903), followed by the process proceeding to the step S608.

FIG. 9C is a flowchart showing the procedure of the second print job which is executed in the step S902 in FIG. 9A. Processes in steps S601 to S609 in FIG. 9C are the same as those in the steps S601 to S609 in FIG. 6, and therefore, only features different from the processes in FIG. 6 will be described below.

Referring to FIG. 9C, as a result of the determination in the step S601, when the sheet bundle Sb2 is to be discharged onto the saddle tray 412, the CPU 206 determines whether or not the stacking mode selected when the second print job is to be executed is the same as the stacking mode when the first print job was executed based on the stacking mode information stored in the work memory 207 in the step S903 (step S904).

As a result of the determination in the step S904, when the stacking mode selected when the second print job is to be executed is the same as the stacking mode selected when the first print job was executed, the CPU 206 determines whether or not the user who has ordered execution of the first print job and the user who has ordered execution of the second print job are the same based on the user information stored in the work memory 207 in the step S903 (step S905).

As a result of the determination in the step S905, when the users are not the same, the process proceeds to the step S603, and then the processes in the steps S603 to S607 are carried out. As a result of the determination in the step S607, when the OK button 702 a, 702 b has been depressed, the CPU 206 stores the stacking mode information and the user information in the work memory 207 (step S906), followed by the process proceeding to the step S608. As a result of the determination in the step S905, when the users are the same, the process proceeds to the step S906 with the steps S603 to S607 skipped.

As a result of the determination in the step S904, when the stacking mode selected when the second print job is to be executed is not the same as the stacking mode selected when the first print job was executed, the process proceeds to the step S603 with the step S905 skipped.

According to the processes in FIGS. 9A to 9C, when the stacking mode selected when the second print job is executed is the same as the stacking mode selected when the first print job was executed, and the user who ordered execution of the first print job and the user who ordered execution of the second print job are the same (steps S904 and S905), the confirmation display screen 700 a or the confirmation display screen 700 b is not displayed when the second print job is to be executed.

In other words, the confirmation display screen 700 a or the confirmation display screen 700 b is displayed only when the first print job is to be executed, and hence the user does not have to see the confirmation display screen 700 a or the confirmation display screen 700 b each time a print job is to be executed. This reduces time and effort for the user.

A description will now be given of a display process which is a third variation of the control method for the image forming apparatus according to the embodiment of the present invention.

FIG. 10 is a flowchart showing the procedure of a third variation of the display process in FIG. 6.

Processes in steps S601 to S609 in FIG. 10 are the same as those in the steps S601 to S609 in FIG. 6, and therefore, only features different from the processes in FIG. 6 will be described below. It should be noted that the process in FIG. 10 is carried out, for example, when the sheet bundle stacking unit 411 does not have the mode sensor 503, and the stacked-sheet presence-absence sensor 504 is used to detect whether the normal mode or the through mode is selected as the stacking mode.

As a result of the determination in the step S601, when sheet bundles Sb are to be discharged onto the saddle tray 412, the CPU 206 determines whether or not the number of sheet bundles Sb to be discharged onto the saddle tray 412 is two or more (step S1001). As a result of the determination in the step S1001, when the number of sheet bundles Sb to be discharged onto the saddle tray 412 is two or more, the CPU 206 executes the print job and discharges one of the sheet bundles Sb onto the saddle tray 412 (step S1002).

Then, based on the result of detection by the stacked-sheet presence-absence sensor 504, the CPU 206 determines whether or not the through mode is selected as the stacking mode (step S603). Specifically, when one of the sheet bundles Sb is discharged onto the saddle tray 412, and the stacked-sheet presence-absence sensor 504 detects that the discharged one of the sheet bundles Sb is stacked on the saddle tray 412, the CPU 206 determines that the normal mode is selected as the stacking mode. On the other hand, when one of the sheet bundles Sb is discharged onto the saddle tray 412, but the stacked-sheet presence-absence sensor 504 detects that no sheet bundle Sb is stacked on the saddle tray 412, the CPU 206 determines that the through mode is selected as the stacking mode.

As a result of the determination in the step S603, when the through mode is selected as the stacking mode, the process proceeds to the step S604, and when the through mode is not selected as the stacking mode, the process proceeds to the step S605. As a result of the determination in the step S1001, when the number of sheet bundles Sb to be discharged onto the saddle tray 412 is one, the process proceeds to the step S608 with the processes in the steps S1001 and S603 to S607 skipped.

According to the process in FIG. 10, when the number of sheet bundles Sb to be discharged onto the saddle tray 412 is two or more (step S1001), and one of the sheet bundles Sb is discharged onto the saddle tray 412 (step S1002), whether or not the through mode is selected as the stacking mode is determined based on a result of detection by the stacked-sheet presence-absence sensor 504 (step S603). The image forming apparatus 101 is usually equipped with the stacked-sheet presence-absence sensor 504 which is for use in determining whether or not sheet bundles Sb are stacked on the saddle tray 412, and hence whether the normal mode or the through mode is selected as the stacking mode is determined without additionally providing the image forming apparatus 101 with any new device or the like.

Although in the embodiment described above, the state in which the stopper unit 501 lies in the position in FIG. 5A is referred to as the state in which “the stopper is attached”, and the state in which the stopper unit 501 lies in the position in FIG. 5B is referred to as the state in which “the stopper is removed”. However, when the stopper unit 501 is configured to be openable and closable like a door, a state in which the door is closed is a state in which “the stopper is attached”, and the state in which the door is opened is the state in which “the stopper is removed”.

Other Embodiments

Embodiment(s) of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No. 2014-156081, filed Jul. 31, 2014, which is hereby incorporated by reference herein in its entirety. 

What is claimed is:
 1. An image forming apparatus comprising: a printing unit configured to print an image on a sheet; a conveying unit configured to convey a sheet bundle including a sheet on which the image has been printed by said printing unit; a discharging tray configured to have the sheet bundle, which has been conveyed by said conveying unit, stacked thereon and have a stopper that prevents the stacked sheet bundle from falling onto a floor; a detection unit configured to detect a state of the stopper; and a notification unit configured to provide notification to a user based on a result of the detection by said detection unit.
 2. The image forming apparatus according to claim 1, wherein the state detected by said detection unit is a state in which the stopper is attached to the discharging tray in a position to hold the sheet bundle or a state in which the stopper is not attached to the discharging tray in the position to hold the sheet bundle.
 3. The image forming apparatus according to claim 1, wherein when the state detected by said detection unit is a state in which the stopper is not attached to the discharging tray in a position to hold the sheet bundle, said notification unit displays a first message.
 4. The image forming apparatus according to claim 3, wherein the first message informs the user that the stopper is not attached to the discharging tray in the position to hold the sheet bundle.
 5. The image forming apparatus according to claim 1, further comprising a determination unit configured to determine the number of sheet bundles that are conveyed by said conveying unit, and wherein said notification unit displays a second message when the state detected by said detection unit is a state in which the stopper is attached to the discharging tray in a position to hold the sheet bundle, and the number of sheet bundle determined by said determination unit is equal to or greater than a predetermined value.
 6. The image forming apparatus according to claim 5, wherein the second message informs the user that the stopper is attached to the discharging tray in a position to hold the sheet bundle.
 7. The image forming apparatus according to claim 1, wherein said notification unit provides the notification before printing is started by said printing unit.
 8. The image forming apparatus according to claim 1, further comprising an authentication unit configured to perform authentication of the user, and wherein said notification unit provides the notification in response to the user being successfully authenticated by said authentication unit.
 9. The image forming apparatus according to claim 1, further comprising a judgment unit configured to, when a second print job is to be executed after a first print job is executed, judge whether the notification by said notification unit is necessary based on whether a user who has ordered execution of the first job and a user who has ordered execution of the second job are the same.
 10. A control method for an image forming apparatus which has a printing unit that prints an image on a sheet, a conveying unit that conveys a sheet bundle including a sheet on which the image has been printed by the printing unit, and a discharging tray on which the sheet bundle conveyed by the conveying unit is stacked and which has a stopper that prevents the stacked sheet bundle from falling down to a floor, comprising: a detection step of detecting a state of the stopper; and a notification step of providing notification to a user based on a result of the detection in said detection step.
 11. A non-transitory computer-readable storage medium storing a program for causing a computer to execute a control method for an image forming apparatus which has a printing unit that prints an image on a sheet, a conveying unit that conveys a sheet bundle including a sheet on which the image has been printed by the printing unit, and a discharging tray on which the sheet bundle conveyed by the conveying unit is stacked and which has a stopper that prevents the stacked sheet bundle from falling down to a floor, the control method comprising: a detection step of detecting a state of the stopper; and a notification step of providing notification to a user based on a result of the detection in the detection step. 